Dual operation tank filling fitting with automatic shut-off

ABSTRACT

A self-contained tank filling fitting having dual operation wherein the fitting may be used with a gravity fluid supply system or a pressurized fluid supply system. The fitting includes an elbow having an upper end closed by a removable cap, and a pressurized filling port located in the bend of the elbow aligns with a tank port to reduce resistance to pressurized fluid filling. An automatic differential pressure valve controlled by a float operated vent automatically closes the pressurized filling port upon the tank being filled.

This is a division of application Ser. No. 591,257 filed Mar. 19, 1984,now U.S. Pat. No. 4,611,618 issued Sept. 16, 1986.

BACKGROUND OF THE INVENTION

Frangible fluid fittings and couplings are commonly employed in the fuellines of aircraft. The purpose of such fittings is to minimize theescape of fuel during crashes, and such crash-worthy fittings andcouplings are often employed to connect the several fuel tanks commonlyused in aircraft of many types.

Crash-worthy fittings normally use a spring biasd self-closing valvewhich is held in the open position by a detent or stop which senses thepresence of other fitting components. Upon the fitting being subjectedto excessive forces, the fitting will fracture and portions thereofseparate permitting the detent to be released that the valve may close.

A disadvantage with known crash-worthy fittings and couplings resultsfrom the typical construction wherein the detent is located at only oneposition on the fitting. Thus, as the direction of forces on the fittingand the nature of relative component movement cannot be predicted duringa crash, it is possible that only partial separation of the fittingcomponents may occur, and if such partial separation results at alocation of the fitting as does not produce detent movement the valvewill remain in the open position even though fluid is escaping throughother portions of the fractured fitting. Conventional crash-worthyfittings can only insure 100% operation if the components sensed by thedetent fully separate, which does not necessarily occur during eachimpact.

It is an object of the invention to provide a frangible fluid fittingwhich releases the self-closing valve upon the occurrence of minorfracturing and relative part movement, and regardless of the directionor location of the fracture with respect to the valve retaining detent.

Another object of the invention is to provide a crash-worthy fluidfitting which is of economical construction, yet is more dependable andsensitive in operation than prior crash-worthy fitting constructions.

An additional object of the invention is to provide a crash-worthy fuelintake fitting of the gravity type which permits fuel tanks to be filledto capacity.

An additional object of the invention is to provide a fuel tank fittingwhich permits tanks to be filled either by gravity or pressurized supplysystems, and wherein the tanks may be filled to the maximum, and whenusing the pressurized supply, a flow control valve is automaticallyclosed upon the tank filling.

In the practice of the invention two primary components of a fitting orcoupling are interconnected by frangible means, such as pins, bolts,screws, weak cross sections, etc. The interconnection components mayconsist of the halves or primary parts of a coupling, or may consist ofa fitting mounting plate attached to the tank and an inlet, port,extension or the like attached thereto. A self-closing valve isassociated with one or both of the parts, and a detent retains the valvein an open position during normal operation.

At the surface at which the parts are interconnected an annular recessis defined in one part surrounding the flow passage. This recess isfilled with hard balls, and the balls are retained within the recess bythe attachment surface of the other part. The valve retaining detentengages the balls and is held in the valve open position thereby.

In the event of a crash or impact causing the frangible elements tofracture and permitting the fitting or coupling parts to even partiallyseparate at the attachment surface, the balls are, at least, partiallyreleased from the recess, and are no longer sufficiently "compressed" tomaintain the valve detent in the open position. The fitting valve closessealing the fitting against fluid flow.

The use of the balls insures valve operation regardless of the directionof fracture or fitting part separation relative to the flow passageaxis. Thus, even though only a single valve retaining detent isemployed, the apparatus is sensitive to separation at the attachmentsurface at any location throughout the full 360°.

One of the crash-worthy fittings in accord with the invention is of thetank-filling type such as used with aircraft, and permits the fuel tankto be fully filled even though the filling port is located on the sideof the tank below its uppermost regions. The fitting includes anextension extending even with the top of the tank, and the use of thisextension simplifies refueling where a pressure system is not available,and permits maximum tank capacity.

An embodiment of the aforedescribed tank filling and extension fittingincludes a port for alternatively permitting pressurized tank filling.The pressurized port includes a differential pressure-operated valveassociated with venting means which closes the valve and terminatesfilling upon the tank capcity being reached.

In the practice of the invention a dependability is achieved forcrash-worthy fittings and couplings not heretofore possible, and theobjects of the invention have been attained by the inventive concepts.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned objects and advantages of the invention will beappreciated from the following description and accompanying drawingswherein:

FIG. 1 is an elevational, sectional view of a refueling gravity-typefitting in accord with the inventive concepts, the valve being held inthe open position,

FIG. 2 is an elevational, detail, sectional view taken along SectionII--II of FIG. 1,

FIG. 3 is an enlarged, elevational, detail sectional view of theattachment surface and frangible fasteners as taken along SectionIII--III of FIG. 1,

FIG. 4 is a plan view, partially sectioned, illustrating a couplingutilizing the inventive concepts of the invention,

FIG. 5 is an elevational, partially sectioned view of the coupling ofFIG. 4 as taken along Section V--V of FIG. 6,

FIG. 6 is an elevational, sectional view as taken along Section VI--VIof FIG. 5,

FIG. 7 is an elevational, sectional view of another embodiment of theinvention as utilized with a refueling fitting capable of both gravityand pressurized supply,

FIG. 8 is a detail, elevational view of the float structure as takenalong Section VIII--VIII of FIG. 7, and

FIG. 9 is a plan sectional view taken along Section IX--IX of FIG. 7.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 an embodiment of the invention is illustrated as used with afitting for filling a fuel tank, such as in a helicopter. In thedrawings, the fuel tank is represented at 10 and includes a side wall12, and an upper wall 14. A vent, not shown, is mounted in the upperwall whereby air may be vented from the tank as it is filled and a floatis utilized with the vent to prevent fuel loss. Such venting devices arccommonly known.

An opening 16 is defined in the tank side wall for receiving therefueling fitting 18. The fitting consists of an annular circular portplate 20 received within opening 16 having attached thereto the elbowextension 22.

The shouldered port plate 20 is mounted within the tank opening by aplurality of spaced bolts 24, and the port plate includes a flow passage26 which may be selectively closed by the pivotally mounted valve 28attached to the inside of the port plate on pivot 30. The torsion spring32 biases the valve 28 toward the closed condition wherein the valveengages the inner surface of the port plate to close passage 26.

The valve 28 is maintained in the open position illustrated in FIG. 1 byan axially movable detent pin 34 slidably received within the bore 36.The inner end of the detent pin engages the support 38 for the valve,while the outer end 40 of the detent is disposed toward the extension22. The port plate 20 also includes an attachment surface 42 of anannular configuration which is intersected by the bore 36, the outer end40 of the detent extending beyond the attachment surface.

The elbow extension 22 includes a horizontally disposed portion havingan attachment surface 44 defined thereon engaging the surface 42, and anannular seal 46 produces a fluid-tight connection between the port plate20 and extension 22. The elbow extension is attached to the port plateby a plurality of circumferentially spaced screws 48, FIG. 3, extendingthrough holes 50 defined in the port plate and threaded into holes 52formed in the elbow extension. The screws 48 are each provided with aweakened frangible section 54.

The elbow extension 22 includes upwardly extending portion 56 which isprovided with a flange 58 whereby a cap 60 may be used to seal the upperopen end of the extension portion The cap 60 uses movable fingers 62 tounderlie the flange 58 to hold the cap in place. As will be apparentfrom FIG. 1, the upper end of the extension 22 is substantially alignedwith the tank top wall 14.

An annular recess 64, FIG. 3, is defined in the elbow extension 22 aboutthe extension's passage 66, and the recess intersects the attachmentsurface 44. A plurality of balls 68, such as ball bearings, are receivedwith the recess 64, and the recess is completely filled with such balls,and further, the balls are maintained under compression by a plungergenerally indicated at 70 which includes a set screw 72 received withinthe port plate threaded bore 74 tightened against a ball 76 which is inalignment with the "valley" between adjacent balls 68. By tightening setscrew 72 the balls within the recess 64, throughout the entire recessconfiguration, are tightly held against each other.

The outer end 40 of the valve retaining detent pin 34 is received withinthe recess 64 and engages the balls 68 therein. Thus, the balls preventmovement of the detent 34 to the left. As apparent in FIG. 1, the elbowextension is provided with a clearance 78 in alignment with the detentpin 34 to receive the detent during valve release.

In use, the assembly will be in the condition shown in FIG. 1. The cap60 will be removed from the extension portion 56, and fuel poured intothe extension enters the tank 10. As the upper end of the extension issubstantially level with the tank upper wall 14, the tank may be fullyfilled even though the filling port opening 16 is located well below theupper wall. Upon the tank being filled the cap 60 is applied to the openend in a sealed relationship.

In the event of a crash high impact forces may be imposed upon theextension elbow 22 tending to rip the fitting from the tank. In suchevent the weakened section 54 of the frangible screws 48 will permitthose screws near the greatest tension to fracture at the sections 54,and such fracturing will result in separation of the attachment surfaces42 and 44. This separation will permit some of the balls 68 to bedisplaced within or escape from the recess 64, and such movement by theballs will permit the detent 34 to be forced into the recess 64 andclearance 78 by spring 32 permitting the valve 28 to pivot to its closedcondition.

As the recess 64, and balls 68, extend 360° about the flow passages 26and 66, the valve 28 will be closed immediately upon separation in anydirection of the attachment surfaces 42 and 44. Thus, by the use of thedetent retaining balls 68 only a single detent is required to operatethe valve and yet a full 360° sensitivity to fracturing is achieved.

The aforedescribed inventive concept may also be utilized in a fluidcoupling, and FIGS. 4-6 illustrate an example of such use. Couplingparts 80 and 82 are of identical configuration and are associated withhose or pipe, not shown, attached to the portions. In the describedembodiment the coupling is mounted within a partition 84, but ifdesired, the coupling may be free and merely used to interconnectflexible hose line.

Each coupling part includes a passage through which fluid flow iscontrolled by a rotatable spherical-type valve. The valves 86 pivot upondiametrical opposed pivots 88 and torsion springs 90 bias the valvesabout the pivot pin axes toward the closed condition. Abutments 92, FIG.6, defined on the valves cooperate with stop pins 94 to position thevalves in the full open position illustrated, and 90° rotation of thevalves also causes simular abutment surfaces to engage the pins 94 toterminate rotation of the valves in a closed direction.

The coupling parts engage at attachment surfaces and 96 and 98, whichare sealed by the O-ring 100. A recess 102 defined in part 80intersecting surface 96 is filled with balls 104 engaging attachmentsurface 98. The coupling parts are maintained in assembled relationshipby the frangible H-shaped pins 106 circumscribing the coupling, and thepartition 84 is received within the groove defined between flanges 108.

A pair of detent pins 110 are utilized to maintain the valves 86 in theopen condition. As apparent in FIG. 4 the pins 110 are each slidablyreceived within a coupling part, and engage shallow recesses 112 definedin the valves when the valves are held in the fully open positionillustrated. The outer ends of the detents enter the recess 102 and bearagainst the balls 104 therein.

In the event of a crash, at least some of the pins 106 may fracturepermitting separation of the coupling parts at the attachment surfaces96 and 98. This separation will release balls 104 from the recesspermitting the detents 110 to be forced into the recess 102 by the sidesof recesses 112 due to the biasing action imposed on the valves 86 bythe valve springs 90. The valves 86 immediately pivot to the closedcondition as determined by the stop pins 94.

It will be appreciated from the above that the concept of using theballs to operate the valve detents is adaptable to a coupling as well asto a tank-mounted fitting as shown in FIGS. 1-3.

FIGS. 7-9 illustrate a tank-filling fitting similar to that describedwith respect to FIGS. 1-3, and identical reference numerals areindicated by primes. This fitting is attached to a fuel tank in a manneridentical to the previously described embodiment wherein frangiblefasteners, balls, and a detent valve retainer is used to close the portplate in the event of a crash.

In this embodiment the elbow extension 114 is provided with a lowerattachment portion for attaching the extension to a tank in the mannerdescribed above with respect to FIGS. 1-3 and the extension includes aport 116 whereby a pressurized fuel source may be used to fill theassociated tank if the same is available. Thus, this embodiment of theinvention permits both gravity and pressurized fueling.

Preferably, sight glass 118 is attached to the extension 114, and asight glass, if desired, may also be attached to the elbow extension 22of FIG. 1.

The port 116 includes an annular sleeve 120 attached to thc elbowextension by screws 122 and which mates with a standard pressure fuelingnozzle, and a spider 124 having ports 126 supports the poppet valve 128and compression spring 130 biases the poppet valve to a closed sealedrelationship with the sleeve valve seat 132. The valve 128 prevents theloss of fluid when the nozzle is disconnected.

The port 116 is further protected by the removable cap 134 which isoperated by the manually operated handle 136. The cap includes an innerportion 138 supporting retaining contractable wire 140 located in recess142, and upon exerting an outward pull on the handle 136 the innerportion 138 moves to the left to contract wire 140 over the outerportion ridge 144 to align the recess 146 with the balls 148 permittingrelease of the outer portion 150 from the recess 152 whereby the entirecap may be removed from port 116. Reinstalling the cap reverses theaforedescribed sequence.

Flow through the port 116 is controlled by the valve 154 adapted to seatagainst the spider surface 156. The valve 154 is controlled by adifferential pressure actuator which includes chamber 158 mounted on theelbow extension, the left side of which includes the flexible diaphragm160 supporting the valve. Compression spring 162 endeavors to bias thevalve toward the left into a closed condition wherein the valve 154engages the surface 156.

The upper portion of the extension 114 includes a chamber 164 receivinga float 166 which controls valve 168 located at the upper end of thevent passage 170. Additionally, the chamber 164 is vented to theatmosphere by vent check valve 172 which includes a small float wherebyair may be exhausted through the vent, but the float prevents liquidfrom flowing therethrough.

The vent passage 170 communicates through the passages 173 and 175, FIG.9, with the interior of the expansible chamber 158 whereby the chamberwill be in communication with the chamber 164 except when the tank isfull.

In operation, the filling port 116 is rendered accessible by lifting andpulling on the handle 136 to remove the cap 134 therefrom. Thereupon,the nozzle of the filling hose is inserted into the port 116 whichdisplaces the poppet 128 to the right. Upon the commencement of the flowfuel flowing through the port 126 will bias the valve 154 to the right,and from the surface 156. In this manner fuel will flow into the elbowextension 114 and the associated fuel tank.

As the tank is filled, air within the extension 114 is vented throughthe vent valve 172. At the final stages of filling the fuel will enterthe chamber 164, raise float 166 and close valve 168. Thereupon, thedifferential expansible chamber 158 is no longer being vented to chamber164 and the small bleed orifice 174 located within the rivet 176 permitsthe interior of the chamber 158 to fill with fluid under the pressureexisting at the valve 154. As the pressure within the chamber 158equalizes to the fluid pressure acting on on valve 154 the area of thediaphragm 160 is sufficient to force the valve 154 to the left closingthe valve and terminating flow into the fitting and tank. The operatorthen removes the nozzle from the filling port and replaces the cap 134.

As will be appreciated, the aforedescribed embodiment of a frangiblefitting permits both gravity and pressure refueling and while pressurerefueling is most desirable, smaller facilities having only gravityrefueling are still capable of servicing the aircraft.

Various modifications to the inventive concepts may be apparent to thoseskilled in the art without departing from the spirit and scope of theinvention.

We claim:
 1. A self-contained tank filling fitting for use with gravityand pressurized fluid supply systems for filling a tank having a sidewall, an upper wall and a port defined in the side wall below the upperwall comprising, in combination, an annular port plate mounted withinthe tank port having a passage and an annular attachment surfacedircumscribing said passage, a filling extension of an elbowconfiguration including an upwardly extending portion having an upperfilling end adapted to be closed by a removable cap for gravity filling,an attachment portion having an axis transverse to said upwardlyextending portion and an intermediate elbow portion, an annularattachment surface defined on said attachment portion sealingly engagingsaid port plate attachment surface, fasteners attaching said extensionupon said port plate, a pressurized filling port defined in saidextension intermediate elbow portion and in axial alignment with saidattachment portion for receiving a pressurized fluid fitting, a flowcontrol valve within said filling port operable between open and closedpositions, a differential pressure operated actuator operativelyconnected to said flow control valve, an extension chamber defined insaid extension adjacent said upper filling end, an atmosphere ventdefined in said extension upper filling and establishing communicationsbetween said chamber and the atmosphere, a vent valve within saidextension chamber in communication with said chamber and said actuatorpositionable between actuator venting and non-venting positions, a floatwithin said chamber operatively connected to said vent valve within saidextension chamber and adjacent said filling end, and a bleed orificeestablishing communication between the tank and said actuator wherebyfluid flowing within said filling port maintains said flow control valvein its open position and closing of said vent valve to its non-ventingposition by said float causes said actuator to move said flow controlvalve to its closed position whereby the tank can be filled by gravitythrough said upper filling end and by pressure through said pressurizedfilling port.
 2. In a tank filling fitting as in claim 1, said actuatorcomprising an expansable chamber communicating with said vent valve andorifice and a diaphragm defining a portion of said chamber, saiddiaphragm supporting said flow control valve.
 3. In a tank fillingfitting as in claim 1, said filling port including a spring biasedself-sealing protective valve openable by a fluid supply fillingattached to said filling port, and a removable protective cap defined onsaid extension within said filling port.